Method of rendering textile materials



METHOD OF RENDERING TEXTILE MATERIALS F UNGICIDAL AND THE PRODUCTS THEREBY PRODUCED Sylvan I. Cohen, Flushing, and Martin S. Frant, Ossining, N.Y., assignors to Gallowhur Chemical Corporation, New York, N.Y., a corporation of New York No Drawing. Application December 27, 1954 Serial No. 477,922

4 Uaims. (Cl. 117-138.5)

The present invention relates to textile materials havmg a germicidal precipitate of a water-insoluble quaternary ammonium Z-mercaptobenzothiazolate formed in situ in and upon the fibers thereof and to a two-step method of rendering such textile materials durably germicidal. This application is, in part, a continuation of Shibe et al. application Serial No. 402,604, filed January 6, 1954, now abandoned, for Quaternary Ammonium lsvlercaptobenzothiazolates and Process for Preparing the ame.

It is known to treat textile fabrics with compounds which are intended to render these materials mildewproof and germicidal. Insofar as such compounds are watersoluble, they are of relatively little value and are rapidly leached by moisture. Insofar as water-insoluble com pounds are concerned, it is a diflicult problem to apply these in such manner that the treated fabric has any rea sonable amount of germicidal durability. These insoluble compounds are substantially only in the category of coating materials as they do not appreciably penetrate into and become an integral part of the textile materials or the fibers thereof. It has been the practice, so far as we are aware, to apply mildewproofing and germicidal agents to textile materials by passing the textile materials through a suspension or solution of the chemical compound in a single step, but we have found that such a procedure is inferior and is incapable of producing the results of our present invention.

It is, accordingly, a primary object of the present invention to render textile materials mildewproof, fungicidal and bactericidal in such manner that exceptional penetration is eifected and the treated fabrics retain their fungicidal properties for a long period of time.

Another object of the invention resides in applying separate unreacted components to textile materials in succession so as to produce a precipitate in situ in and upon the fibers of the textile material while at the same time achieving exceptional penetration so that the treated fabrics retain their properties over a long period of time.

More specifically, an object of the invention resides in treating a textile material, such as cotton duck, with an aqueous solution of a germicidal quaternary ammonium compound and then with an aqueous solution of sodium Z-mercaptobenzothiazolate, the treated fabric having exceptional mildewproof, germicidal and fungicidal properties with great resistance to leaching, as the compound is formed and deposited in and on the fibers in such manner as to be Water-insoluble and integrally bound with the fibers themselves.

Other and further objects and advantages will be understood from what follows or will be appreciated by those skilled in this art.

According to the present invention, a first solution is made up of a germicidal quaternary ammonium compound which may be any of those types or particular compounds specified in application Serial No. 402,604 aforesaid. Preferably, this solution is made up by dissolving alkyl dimethyl benzyl ammonium chloride (benzalkonium chloride) in water, preparing a second solution containing sodium 2-mercaptobenzothiazolate in water and then successively passing cotton duck or other textile fabric through the individual solutions. When this is done, a Water-insoluble precipitate or alkyl dimethyl benzyl ammonium Z-mercaptobenzothiazolate is formed in and upon the fibers of the cotton duck or other textile material in such a manner as to become, for all practical purposes, an integral part of the textile material.

TABLE 1 Efiect of rinsing during Z-bath process upon bacteriostatic. activity of cotton treated with 5% of alkyl dimethyl 3,4-dichlorobenzyl ammonium chloride and sodium 2- mercaptobenzothiazolate Average Treatments zone of inhibition,

mms.

(1) Treated-no rinse 5. 3 (2) Treated-air dried overmght-thenS rinses. 4. 0 (3) Treated3 rinses while weta1r dried overn ht 3. 5

(4) No treatment 0 Average of 4 replicate 10 mm. cloth discs. Assayed November 18, 1954, using M. pyogenes var. aureus by FDA cir. 198 method.

OoncZusions.The bacteriostatic activity of treatments f3 and 3 in the above table indicates the durability of this antiseptic treating process. The fact that rinsing the wet cloth immediately after processing (treatment 3) did not Slg'lllllcantly affect activity over drying before the rinses (treatment 2) indicates that the chemical is durably deposited in the fibers of the fabric. Apparently the tenacity of the chemical in or on the fiber is such that it does not require drying for durability. (However, some loss results from rinsing as noted in comparing treatments 2 and 3 with No. 1.) These results were confirmed in a further test.

Since the precipitate is composed of water-insoluble material, it resists leaching over long periods of time and, therefore, the textile material is permanently character ized by mildewproof, germicidal and fungicidal properties.

We have found that this two-step method has important advantages over the one-step method heretofore used not only because the treated fabric retains its properties for an indefinitely long period of time but because the germicidal character of the quaternary ammonium compound is materially enhanced, being greater than either the quaternary ammonium compound or the Z-mercaptobenzothiazolate separately.

TABLE 2 Mildew rating after 7 days Treatment Unleashed Leached 24 hours 1% benzalkonium chloride 0 1% mercaptobenzothiazole 0 5 1% benzalkonium 2-mercaptobenzothiezolate 0 0 Mildew ratings:

0=no growth. 1=trace oi mildew; several spots on cloth. 2=s1ight mildew; up to 25% of area. 3=rnoderate mildew; up to 50% of area. 4=abundant mildew; 5010 0% area covered. 5=overgrown and sporulatmg.

In addition, by carrying out the procedure in two steps, as above set forth, the wetting and penetrant properties of the quaternary ammonium compound can be given full effect, whereas such are not available in a product of reaction thereof. The quaternary ammonium Z-mercaptobenzothiazolate, therefore, contains two functional groupings which, in the present invention, serve to enhance and synergize the active functional groupings of the individual components, thereby producing results which are vastly U superior to those which can be obtained by applying an already reacted product directly to the fabric or material.

TABLE 3 One bath Two bath 9. 92? lowoowm 1 Average 014 replicate mm. cloth discs. Assaycd December 2 1954 using Micrococcux pyogenea var. aureus by FDA Cu. 198 Method.

Discussion.Cotton duck was processed by dip-squeezing through solutions of Puratized 1123 which were prepared at various concentrations from 0.15% active ingredient. The one-bath solution consisted of the chemical dissolved in hen zene. The two-bath consisted first of the aqueous quaternary dip followed by the aqueous niercaptobe'nzothiazolate. The pickup of the cloth in benzene averaged 62.4% of the dry weight of the fabric and ranged from 6 0,0-63.%. The pickup from the aqueous two-bath averaged 50.2% and rianged from 52.-i58.0% for the different chemical concentrat ons.

For bioassay, random circular discs were unched out of each piece of cloth and placed on agarsee ed with the bacterium. The petri plates were incubated 24 hours at 37 C. and zones of inhibition recorded. The bacteriostatlc activity was then plotted on log paper against the calculated quantity of chemical in the cloth. For example, for the l'bath treatment, the wet pickup from the 5% chemical solu tion was 63.8% of the dry weight of the fabric, or 63.8 .05:3.19% chemical in the cloth. Unfortunately, no chemical method is available to analyze the cloth directly for concentration of this new chemical.

The plotted bacteriostatic data showed a straight line relationship between the logarithm of the chemical concentration and the germicidal effectiveness. The curves from both methods of application were parallel but the 2-bath process was significantly more effective. The activity shown in the above table was interpolated from the curves at arbitrary concentrations between 0.12% to illustrate the superiority of the 2-bath process.

The procedure also is of benefit in that it is extremely simple and economical as it is only necessary to prepare the individual aqueous solutions without being concerned about reacting them and obtaining good yields of the reaction product. The two-step method of the invention is, moreover, carried out at room temperature under ordinary prevailing temperature conditions and thus requires no special apparatus, equipment or control.

The invention is illustrated by the following specific example Without limiting it thereto:

EXAMPLE A first solution was prepared containing 6 grams of alkyl dimethyl benzyl ammonium chloride (benzalkonium chloride) to each 200 milliliters of water.

A second solution was prepared containing 5 grams of sodium 2-mercaptobenzothiazolate to each 200 milliliters of water.

Cotton duck was passed through the first solution at a rate sufficiently slow to permit saturation with the pene trant solution of the quaternary ammonium compound. Excess solution was squeezed out by pressure and the cotton duck then passed through the second solution, whereupon a precipitate of water-insoluble alkyl dimethyl benzyl ammonium 2-mercaptobcnzothia'zolate was formed in situ in and on the fibers of the cotton duck as a permanent integral part thereof. The thus treated material was allowed to dry in the air and produced a cloth that was bactericidal, fungicidal and resistant to leaching.

It is to be understood from the foregoing that any suitable water-soluble quaternary ammonium compound may be employed so long as it has germicidal or fungicidal properties. While benzalkonium chloride is one of the preferred quaternary ammonium compounds dueto its ready availability and low price, the invention is not limited to the use of such since there are other quaternary ammonium halides which are eminently satisfactory in carrying out the invention. Such include, for instance, lauryl pyridinium chloride, cetyl trimethyl ammonium bromide, dodecylbenzyl trimethyl ammonium chloride and quaternary ammonium compounds which are halogen-substituted in the benzene ring of the behz'yl group, such as alkyl dimethyl 3,4-dichlorobenzyl ammonium chloride and alkyl dimethyl 2,4-dichlorobenzyl ammonium chloride, as well as mixtures of such quaternary ammonium compounds. The invention also applies to quaternary ammonium compounds of the type represented by para-diisobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride (Hyamine 1622) and a mixture of soya trimethyl ammonium chloride and dicoconut dimethyl ammonium chloride (Arquad S-2C). Likewise, the invention includes the use of Z-mercaptobenzothiazole and its Water-soluble salts, such as sodium 2-rnercaptobenzothiazolate. When 2 mercaptober'iz'othiazole is employed in the invention, it is first converted into its sodium or other suitable water-soluble salt as by means of sodium hydroxide.

In the preferred mode of practicing the two-step method in accordance with the invention, it hasbee'n found best to pass the textile fabric or material first through the aqueous solution of the quaternary ammonium compound and then through the aqueous solution ofthe mercaptobeiizothiazolate as, in this way, full advantage is taken of the penetrant and wetting properties of the quaternary ammonium compound so that, when the fabric or material is subsequently passed through the mercaptobenzothialoate solution, reaction occurs to form a Water-insoluble precipitate in situ in and upon the fibers. It is, however, within the purview of the invention to reverse the order of steps by first subjecting the textile fabric or material to the mercaptobenzothiaz'olatc solution and then to the quaternary ammonium compound solution, although we have found that this procedure is somewhat less desirable and effective than the preferred procedure but, nevertheless, produces useful and satisfactory results. Instead of treating a finished fabric or material, the procedure may be applied to the fibers or yarn which are then woven or otherwise formed into the finished piece goods or articles.

The invention may also be considered as based upon the impregnation or saturation of the textile fabric or material with a germicidal water-soluble quaternary ammonium compound and the insolubilization of the said germicidal quaternary ammonium compound directly in and upon the fibers of the textile material, this procedure acting to produce a water-insoluble precipitate in situ so that exceptional mildewproof, germicidal and fungicidal properties are imparted to, and conferred u on, the fabric and its fibers by employing a Z-mercaptobehZothiazolate solution as the insolubilizing and hiring agent for the germicidal and fungicidal quaternary ammonium compound which has already been applied to the textile material. Exceptionally good results are obtained due to the fact that the mercaptobenzothiazole itself has useful pesticidal properties and has a synergistic action on the quaternary ammonium compound. The product of reaction formed in and on the fibers has greatly enhanced fungicidal and pesticidal properties which are re tained for an unusual length of time so that it is ordinarily not necessary to re-treat fabric or fibers after treatment in accordance with the invention. The finished fabric also has the advantages that ordinary fluids used for dry cleaning do not have any appreciable solvent action upon the quaternary ammonium mercaptobenzothiazolate and hence, treated fabrics may be dry-cleaned, washed and the like without serious loss of the compound and the properties imparted thereto.

The invention is defined by the appended claims;

We claim:

1. A two-step method of rendering a textile material durably mildewproof, germicidal and fungicidal, which 5 comprises forming in situ in and on the fibers of the textile material a water-insoluble quaternary ammonium 2- mercaptobenzothiazolate by passing the textile material successively in either order through separate aqueous solutions, one of which is an aqueous solution of a germicidal quaternary ammonium compound and the other of which is an aqueous solution of a water-soluble 2-mercaptobenzothiazolate, said quaternary ammonium compound synergistically reacting, upon contact with said 2- mercaptobenzothiazolate to form said quaternary ammonium 2-mercaptobenzothiazolate which becomes an integral and leach-resistant part of the textile material.

2. The method of claim 1, in which the textile material is first passed through the aqueous solution of the quaternary ammonium compound to utilize the full penetrant and wetting action thereof.

3. The method of claim 1, in which the quaternary ammonium compound is benzalkonium chloride.

4. A textile material prepared in accordance with claim 1, and characterized by having in and on the same at least 0.5%, calculated on the basis of the dry weight of the textile material, of water-insoluble quaternary ammonium Z-mercaptobenzothiazolate.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A TWO-STEP METHOD OF RENDERING A TEXTILE MATERIAL DURABLY MILDEWPROOF, GERMICIDAL AND FUNGICIDAL, WHICH COMPRISES FORMING IN SITU IN AND ON THE FIBERS OF THE TEXTILE MATERIAL A WATER-INSOLUBLE QUATERNARY AMMONIUM 2MERCAPTOBENZOTHIAZOLATE BY PASSING THE TEXTILE MATERIAL SUCCESSIVELY IN EITHER ORDER THROUGH SEPARATE AQUEOUS SOLUTIONS ONE OF WHICH IS AN AQUEOUS SOLUTION OF A GERMICIDAL QUATERNARY AMMONIUM COMPOUND AND THE OTHER OF WHICH IS AN AQUEOUS SOLUTION OF A WATER-SOLUBLE 2-MERCAPTOBENZOTHIAZOLATE, SAID QUATERNARY AMMONIUM COMPOUND SYNERGISTICALLY REACTING, UPON CONTACT WITH SAID 2MERCAPTOBENZOTHIAZOLATE TO FROM SAID QUATERNARY AMMONIUM 2-MERCAPTOBENZOTHIAZOLATE WHICH BECOMES AN INTERGRAL AND LEACH-RESISTANCE PART OF THE TEXTILE MATERIAL. 